\input{preamble-standalone.ltx}
\begin{document}

% Ex. No. 177 (Section 21.2.1 : Example with \tkzname{mark = x})

\begin{tikzpicture}[scale=.75]
        \tkzDefPoints{0/0/O,5/0/A,3/4/B}
        \tkzMarkAngle[size = 4cm,mark = x,
                      arc=ll,mkcolor = red](A,O,B)
        \tkzDrawLines(O,A O,B)
        \tkzDrawPoints(O,A,B)
\end{tikzpicture}

\end{document}